#include<stdio.h>
int main01()
{
	int n, i;
	printf("please enter a integer number,n = ?");
	scanf_s("%d", &n);
	for (i = 2;i < n;i++)
		if (n % i == 0)break;
	if (i < n)printf("%d is not a prime number.\n", n);
	else printf("%d is a prime number.\n", n);
	return 0;
}